Professional material in the collection includes production material for a number of Kelly's projects. This material includes scripts, notes, reviews, contracts and business correspondence. The most extensive material present pertains to the film Invitation to the Dance (1956), including a telegram from Vincente Minnelli; the Kelly-staged ballet Pas de Deux (1959), including letters from A. M. Julien, Ira Gershwin, Beatrice Bretty, and Kelly; and the film Gigot (1961). Other titles for which we have production materials: Tunnel of Love (1951); The Happy Road (1956); Dancing is a Man's Game (1958); The Flower Drum Song (Broadway musical, 1958); Guide for the Married Man (1967); Jack and the Beanstalk (television film); and Hollywood and the Movies (television film). Additional professional material includes files from American Zoetrope studios and the Cheyenne Social Club, files from projects from the 1970s, and other items dating from the 1970s and 1980s.

Manuscripts in the collection include articles written by Kelly for publication in various magazines, such as Sports Illustrated, Seventeen, Parade, and others. These pieces pertain to his personal biography, his dancing, and/or his films.

Correspondence in the collection includes about 45 thank-you letters and telegrams, sent to Kelly between 1944 and 1968. These include items from Ralph Hetzel, Henry Morgenthau, Jr., Chester Bowles, and Bette Davis. Also present 3 letters signed "Bill," sent to Kelly in conjunction with work on the William Saroyan script Crazy Waiter (1954-1955).

Scrapbooks in the collection consist of nine items, created by Kelly. These contain articles, letters, and photographs dating from 1929 to 1955.

Sheet music in the collection is present for over 200 individual musical numbers. Some of these have notations by Kelly.

The collection contains several awards and honors received by Kelly during his life. There are well over 100 plaques, certificates, trophies, and other items.